Provide a way to load directly into a clap app

[epage]

Something like load(impl serde::Serializer) -> clap::App

[aobatact]

Something like load_yaml, load_toml under the feature gate?

[epage]

Hmm, used to dealing with this from all of the other serde angles. Most people are used to using the from_str functions provided by their serializer crate. Some serializer crates do expose their serde::Serializer so you could have a load(serializer: impl serde::Serializer) though I would deem this a lower priority

[epage]

I've updated the issue from being about removing wrappers to about a direct load.